Valve-seat grinder



Sept. 16, 1930.

G. W. FLEMING VALVE S EAT GRINDER Filed Dec. 6, 1927 jwzz;

Patented Sept. 16, 1930 UNITED STATES PATENT OFFICE GEORGE W. FLEMING, OF WORCESTER, MASSACHUSETTS, ASSIGNOE TO FLEMING MA- CHINE COMPANY, DIE WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTS VALVE-SEAT GRINDER Application filed December 6, 1927. Serial No. 238,201.

The principal objects of this invention are to provide a self-centering means for a valve seat grinder;- to provide a centering means cooperating with the pilot of the grinder to hold the stone against vibration and chattering while in operation; and to provide a simple and inexpensive construction for this purpose.

Other objectsand advantages of the invention will appear hereinafter.

Reference is to be had to the accompanymg drawings, in which ig. 1 is a sectional view showing a grinder in position for surfacing or resurfacing a valve seat, said grinder being constructed in accordance with this invention;

Fig. 2 is a similar view of the pilot and split sleeve associated therewith; and

Fig. 3 is a sectional view on the line 3 -3 of Fig. 2 on enlarged scale.

The invention is shown as comprising a valve grinder comprising a sleeve 10, connected by a joint 11 to a flexible or other shaft and having a grindi stone 12. This stone is held on the sleeve y a nut 13 and the sleeve is provided with a central bore 14 in which the end of the mandrel of the pilot 15 is adapted to be received with a tight fit. The pilot is provided with a split ring 16 or the like at the bottom, which can be formed of a single piece of wire set into the groove at the bottom of the tapered pilot for holding thereon a split sleeve 17 having a shoulder 18 at the top.

The split sleeve is provided with slits 19, arranged around the circumference and extending in from opposite ends to a distance a little short of the other end so as to provide an expanding construction. As shown two opposite slits extend in from the top and the rest from the bottom.

In operation the split sleeve is inserted in the valve guide 20 in which it fits snugly until the shoulder 18 rests on the top of the guide valve 20.

It will be noted that as the pilot is of tapering form and the split sleeve 17 is tapering inside to fit it, the forcing down of the pilot will tend'to expand this split sleeve against the interior of the valve guide. The

expansion is not accomplished until the shoulder 18 is lowered into contact with the valve guide, when the pilot is driven in tight, locating the pilot in the center of the valve guide. The sleeve 10 having the grinding stone 12 and connected to aportable drill or the like is thus centered on the pilot 15.

It will be noted that the expandingsleeve can be removed from the valve guide by inserting a hardened pin into an elongated slot 22 in the top of the pilot. This pin is then turned and pulled upward to separate the conical end of the pilot from the expanding sleeve, thus loosening that and allowing the sleeve to be drawn out by the ring 16 at the bottom of the pilot as shown in Fig. 2.

In the use of the device it will be seen that it is self-centering and always accurately centered in position. Also the pilot is firmly held throughout a long surface, thus avoiding chattering and vibration. This insures a true circular cut around the valve seat and one that is accurately centered as well.

Although I have illustrated and described only a single form of the invention I am aware of the fact that modifications can be made therein by any person skilled in the art without departing from the scope of theinvention as expressed in the claim. Therefore,

I do not wish to be limited in these respects,

but what I do claim is In a guide and centering device for a valve seat grinder, the, combination with a pilot having a smooth tapering surface throughout its entire length, of a one-piece sleeve having an interior tapering surface fitting the pilot from one end to the other and havingslits extending from each end toward and beyond the center, said sleeve having a shoulder adapted to engage the top of the usual valve guide when in position and being adapted to be expanded against the interior of the valve guide throughout its length by the pilot when the latter is forced into it. and detachable .means located entirely beyond the end of the GEORGE W. FLEMING. 

